This invention relates to an electronic pricing display system for displaying current pricing information in real time onto shelf display tags or units, and more particularly to such a system in which computer based information in the form of an address code followed by pricing information is transmitted to store shelf tags for display of the pricing information.
Heretofore, such as illustrated in U.S. Pat. No. 4,500,880, dated Feb. 19, 1985, electronic pricing display systems have been utilized for electronically displaying pricing and other specialized information which is associated with a universal product code (UPC) in the fom of a bar code. A plurality of remote price display units are mounted on store shelves adjacent to associated products and each of the plurality of display units is hard wired to a store based computer which carries both power and associated data. Each of the display units shown in U.S. Pat. No. 4,500,880 stores a programmed address code which is verified by information applied by the store based computer before further data is supplied to the display units. An optical scanner reads the UPC bar code and supplies the correct price to a cash register for manual entry by a clerk.
U.S. Pat. No. 4,002,886 to Ronald M. Sundelin dated Jan. 11, 1977 likewise shows an electronic price display unit in which the price displayed is set by the same computer which supplies prices to a point of sale teminal at a cash register, for example, and this insures that whenever the price of an item is changed in the computer memory the price displayed is automatically changed to the same new price. While Sundelin states that the means for connecting the price display unit or tag to the computer may comprise wires or other conductors, electromagnetic transmission and reception, or any combination, the interface shown and described between the store based computer and the price display unit or tag utilizes four conductors or wires between the computer and price display unit including a wire conductor for the power supply, a wire conductor for the transmission of electrically coded information, and a wire conductor for the transmission of clock and reset pulses to the price display unit.